1. Field of the Invention
The present invention relates generally to methods and apparatus for dispensing liquids and, more particularly, to a method and apparatus for very accurately dispensing a preselected amount of liquid in a drop-by-drop fashion.
2. Description of the Prior Art
It is conventional to employ a metering means, such as a pipette, burette, etc., to transfer small preselected amounts of liquid from a supply container to each of a plurality smaller containers. These types of liquid transfering methods are normally carried out manually to attained the needed accuracy because of the visual measurements required.
However, as the number of preselected amounts increases, it becomes increasingly difficult to achieve the desired accuracy because the incidence of human error in measuring increases as the number of measurements per unit time increases. Efforts have been directed at automating the transfer operation, but such efforts have not yielded the desired results of increased accuracy, increased throughout, and lower measurement cost. If the transfer operation could be automated in a satisfactory fashion, it would have applications, for example, in blending and supplying of raw materials, and in blending of catalysts, color formers, sensitizers, etc.